10 JanCurlex vs. Straw
Evaluating Curlex® and Straw Fibers for Erosion Control Blankets
Straw and Curlex® fibers are two common fibers for erosion control blankets. Each fiber type has distinct advantages and reasons why it is selected by end users.
Both straw and excelsior wood fibers are used to produce short-term and long-term erosion control blankets.
In this blog we are going to compare straw fiber to Curlex® wood fibers to explain why these types of erosion control blankets are so popular in the Mid-Atlantic.
Straw is the most common erosion control blanket in Virginia and many other Mid-Atlantic states.
Why is straw matting one of the most popular choices for erosion control blankets?
1. Agricultural straw is a widely available fiber
2. Straw Matting is the most affordable erosion control blanket
3. Straw Blankets meet performance standards for short-term erosion control
Agricultural Straw is a Commodity
Straw blankets are produced from agricultural straw, a by-product of farming operations. Straw fiber is readily available to erosion blanket manufacturers at a low cost, especially when compared to other erosion matting fibers.
Not all agricultural straw, however, can be used to produce erosion control blankets.
Agricultural straw for straw matting must meet quality control standards for age, moisture, length and width.
Straw fibers that are too old will decrease the longevity of the straw blanket. Additionally, straw fibers that are too moist will increase the likelihood of mold which diminishes the blanket’s performance.
Fibers that are too short cannot be properly stitched into the fiber matrix. American Excelsior, for example, specifies that 75% of the agricultural straw for the Premier Straw® Blankets must be 4 inches or greater in length.
Straw fibers should also be wide. A wide straw fiber increases surface area, reducing the impact of droplets onto soil, thus reducing soil erosion. Wide straw fibers also protect seedlings and increase absorption which is important for grass establishment. However, if the straw fiber is too wide and the straw blanket too dense, sunlight won’t be able to penetrate through to the seedlings in the soil.
One of the most important qualities of agricultural straw fiber is that it is 100% weed seed free.
Erosion control blankets stabilize the soil by creating an established turf system. Before an erosion blanket is installed, the soil is seeded. When the seedlings germinate and grow through the erosion control blanket, their roots interlock with the erosion matting fibers to create a stabilized system. If the erosion control blanket’s fibers contain weed seed, those weeds will choke out the seedlings and prevent the site from establishing healthy turf.
Straw Blankets Control Erosion at an Affordable Rate
Straw matting may not be the top performing erosion control fiber, but it does meet the standards for many every-day applications. Straw blankets are suitable for mild slopes and can handle shear stress up to 1.75 lb/ft2.
Different variations of Straw Matting are approved for use by multiple state Departments of Transportation in the Mid-Atlantic.
In Virginia, multiple Single Net Straw Blankets are approved for EC-2 Type 1 for temporary rolled erosion control products and Double Net Straw Blankets are approved for EC-2 Type 2 applications.
In Delaware, American Excelsior’s Premier Straw FibreNet® Double Net (double net straw matting with biodegradable blanket) is an approved rolled erosion control blanket on DelDOT’s Approved Materials List.
And In North Carolina, Straw Erosion Control Blankets are found on NCDOT’s Approved Product List for Blankets and Mats as well as Landscaping Items.
When contractors need an erosion control blanket that is affordable but effective for short term erosion control, Straw Matting is a reliable choice for performance needs and budget requirements.
Curlex® Fiber for Excelsior Blankets
Excelsior Fiber also known as Curlex® is another popular choice for erosion control blankets. Curlex® blankets provide superior erosion control but come at a slight increased cost to the consumer.
What distinguishes Curlex® fibers from other erosion control blankets?
1. Curlex® fibers are curled and barbed
2. Wood fibers swell when they encounter water
3. Curlex® fibers don’t float
Curled and Barbed Wood Fibers
American Excelsior’s patented Curlex® fibers are made from 100% Great Lakes Aspen wood fibers. The end of each wood fiber is curled and barbed which distinguishes it from the flat straw fiber.
The curled wood fibers interlock with each other and with the soil to create an intimate connection. This allows Curlex® erosion control blankets to further connect with the ground, intertwine into the root system and reduce soil erosion.
Curlex® Fibers Swell but Don’t Float
Wet Curlex® fibers swell and interlock to form a strong fiber matrix. This creates intimate soil contact and forces water to flow over the fiber matrix (rather than under). Excelsior fibers also successfully retain moisture, which improves vegetation establishment.
Much like Recyclex®, Curlex® erosion control blankets don’t float during hydraulic events. When your construction site suffers a major rain event, the excelsior blanket clings to the soil so that water flows over the blanket and the soil is retained.
This is a major performance advantage that separates excelsior fibers from other erosion control blankets. Just as the video states, Straw Blankets are successful for many erosion applications. However, if you need erosion control matting for channel flow applications like ditch bottoms, Curlex® is the preferred performance choice.
Two Great Erosion Blankets: what does your application require?
Both Straw Blankets and Curlex® Blankets successfully control erosion, prevent soil loss, and revegetate construction sites.
It is not a question of which fiber is better, but which fiber is better for your application?
If you need assistance with selecting the right blanket for your application, contact our sales team. We can provide you with pricing and technical data that relates to your site so that you can make the best decision for your project.